S
M
T
W
T
F
S
30
74°
49°
31
87°
57°
1
69°
60°
2
66°
58°
3
65°
56°
4
67°
55°
5
73°
56°
6
66°
57°
7
74°
50°
8
82°
49°
9
87°
50°
10
78°
55°
11
71°
53°
12
65°
53°
13
71°
51°
14
74°
52°
15
82°
57°
16
86°
60°
17
88°
59°
18
82°
60°
19
72°
58°
20
73°
59°
21
75°
58°
22
77°
56°
23
78°
58°
24
72°
54°
25
67°
57°
26
65°
52°
27
65°
50°
28
66°
49°
29
64°
48°
30
64°
48°
1
67°
55°
2
68°
53°
3
65°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Portland
Portland's September 2026 forecast shows daily high temperatures ranging from 64° to 88°, with overnight lows between 48° and 60°. The average high for September is 72° with an average low of 54°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Portland. See also: October | November | December.
